I keep getting these 2 codes!!!
Thread Starter
Burning Brakes
Joined: Aug 2003
Posts: 878
Likes: 1
From: Anaheim CA
I keep getting these 2 codes!!!
For the last couple of months now, I've been getting the P0171 and P0174 codes. They both appear together, usually in the morning when driving to work.
They pop up about 1-2 times a week.
They first popped up after I installed a B&B Bullet exhaust a couple months back, but I've had other aftermarket exhausts before that. Even after I removed the Bullet exhaust and installed a Route 66 exhaust, the codes still intermittently pop up.
What should I be checking?
Mike G.
They pop up about 1-2 times a week.
They first popped up after I installed a B&B Bullet exhaust a couple months back, but I've had other aftermarket exhausts before that. Even after I removed the Bullet exhaust and installed a Route 66 exhaust, the codes still intermittently pop up.
What should I be checking?
Mike G.
Tech Contributor
Joined: Oct 1999
Posts: 40,995
Likes: 9,759
From: Charlotte, NC (formerly Endicott, NY)
It means that both banks of the engine are seeing a lean condition. Perform the following:Check for fuel contamination.
- Inspect the HO2S for proper installation.
- Verify the electrical connectors and the wires are secure, and not contacting the exhaust system.
- Test for continuity between the HO2S signal circuit and the low reference circuit.
- Operate the engine at idle.
- Inspect for any missing, loose, or leaking exhaust components forward of the HO2S.
- Inspect for vacuum leaks at the intake manifold, throttle body, and injector O-rings and vacuum hoses.
- Inspect the air induction system and the air intake ducts for leaks.
- Inspect the secondary air injection (AIR) system for leaks, improper air delivery, and for the shut-off valves not closing.
- Inspect the crankcase ventilation system for leaks.
Last edited by Bill Dearborn; Dec 11, 2008 at 01:18 AM.
Melting Slicks
Joined: May 2005
Posts: 3,394
Likes: 12
From: Leon Iowa
St. Jude Donor '06-'07-'08-'09
My sister's 98 Z28 was doing the same thing and codes. I checked everything and couldn't figure out. I finally changed the fuel filter and noticed it was kinda plugged and to my surprise it was fixed. No more code and it's been almost a year.
